In case anyone doubted that the Shturmovik was a tough plane (the Germans are said to have called it the "Betonflugzeug", or "Concrete Plane", supposedly because of its toughness), here is a photo, with more to follow.

That's correct, Massimo. You can see why Sergei Ilyushin wanted the IL-2 to return to metal wings so much; they were immensely strong. He never did want the wooden wings - that was forced upon him by the lack of aluminium, and by the middle of 1944, the IL-2's were once again being produced with metal wings upon Ilyushin's insistence. However, the wooden wing could also take quite a bit of damage, as you can see in the photographs below.